LOFAR, LOw-Frequency ARray, is a radio interferometer constructed by the Netherlands Institute for Radio Astronomy (ASTRON). Its core is located in the village of Exloo and most of its antennas are located within the Netherlands, but the International LOFAR Telescope (ILT) has antennas in Germany, France, Poland, Sweden, UK and Ireland as well. The antennas are arranged in tiles and stations. The density of stations near the core is high resulting in a high sensitivity and the distant international stations provide a high angular resolution. LOFAR is one of the most important pathfinders for the upcoming Square Kilometer Array.